Elevator doors usually have an elevator car door which is provided on the elevator car, and shaft doors provided on each story. When the elevator car moves up to each story, both the elevator car door and the corresponding shaft door (then positioned behind the elevator car door) are opened and closed to allow passengers to get on or off or to continue the movement of the elevator car.
An elevator car door usually has a drive by means of which said elevator car door can be opened and shut. In order to avoid corresponding drives for each shaft door, the elevator car door is designed with entraining means or a dog-type mechanism which engages with corresponding counter entraining means of the shaft door upon reaching a story and opens and shuts said shaft door at the same time. Expanding skate mechanisms, as are described, for example, in EP 0 744 373 B1, are customarily used in this case.
In particular in what is referred to as a high-performance elevator car door, it is essential to avoid rattling and wind noises at very high traveling speeds. Furthermore, elevator doors of this type are intended to open and shut as rapidly as possible. Precise positioning of the entraining means and the counter entraining means with respect to one another is essential in order to avoid such noises and to permit rapid opening and closing of the door.
A further device for entraining a shaft door by an elevator car door, which is actuatable by a door drive, for elevator installations is known from WO 2011/072891.
It is conventionally customary to position entraining means, which are designed as an expanding skate which is attached to the elevator car door, and counter entraining means, which are designed as rollers and are provided on each shaft door, in the vicinity of the door upper edges.
This makes it possible for a fitter to set a desired positioning of the counter entraining means with respect to the entraining means from the elevator car roof. This generally takes place by the elevator car being moved into a position somewhat below a story position such that the expanding skate provided on the elevator car and the rollers which are provided on the shaft door and in which the expanding skate engages for carrying along the shaft door are visible simultaneously for the fitter. This procedure has proven favorable in particular because the upper end of the expanding skate projects over the upper edge of the elevator car.
The fitter sees the position of the expanding skate in a folded-up state, and at the same time identifies the lifting movement of the expanding skate angle member of the expanding skate, from the folded state into the moved-apart coupling or end state. On the basis of this optical information, the fitter is capable of positioning the rollers, which serve as the counter entraining means and between which the expanding skate is intended to engage, in such a manner that, in the unfolded state, the expanding skate angle members each act upon a roller and therefore couple elevator car door and shaft door. Customarily, the two rollers, optionally with further components of a coupling and locking mechanism, are provided here on a carrier plate which is formed with elongated holes. The elongated holes here are positioned in front of corresponding threads formed in the shaft door, and therefore a desired displacement and fixing of the carrier plate with respect to the shaft door is possible using screws which interact with the elongated holes and the threads.
However, in this procedure, a positioning of the counter entraining means, in particular of a carrier plate with two rollers, and of the expanding skate is possible merely in the immediate vicinity of the upper edge of the shaft door or elevator car door. This means that the coupling of elevator car door and shaft door also takes place in the surroundings of the upper edge of the doors, and this, in particular in the case of doors which are to open and close rapidly, results in a relatively severe and nonuniform torque loading of the doors.
Furthermore, the outlay to be expanded on safety is relatively high since the work has to be carried out from the elevator car roof.
Finally, such an installation is considered to be relatively complicated since the positioning of the rollers substantially takes place by sight. In practice, this generally leads to the position of the rollers and of the carrier plate having to be readjusted, which is associated with repeated moving of the elevator car.
EP 1 500 625 A1 describes a method in which the positioning of the rollers on the shaft door is carried out by means of action by expanding skate angle members.